The Abundance and Biting Behaviour of Anopheles merus (Dönitz) in Gokwe South District, Zimbabwe

Abstract

Malaria is a major public health problem in most sub-Saharan countries. Anopheles merus (Dönitz), a saltwater breeding member of An. gambiae complex, is involved in low rate malaria transmission in this region. In this study, female anopheline mosquitoes were collected at Masakadza in Gokwe South District to determine the biting cycle of An. gambiae complex species and the relative abundance of malaria vectors in this area for effective vector sampling and control. Three adult mosquito collection techniques were employed: window trap, knockdown and human-baited tent trap. Peak biting activity by An. gambiae complex species and An. merus during the three months of sampling showed seasonal variations in the biting cycle of these species at Masakadza. The peak of biting activity for An. gambiae complex species occurred at 2200 hours in November 2006, 0300 hours in January 2007, and 2200 hours in March whereas the peak of biting activity for An. merus occurred at 2200 hours in November 2006, midnight in January and March 2007. Anopheles merus was found to be the predominant species accounting for 70% of total collections based on morphological identification. The study also revealed that the resting behaviour of An. gambiae complex species in this area is mainly exophilic with mean hut densities of 0.2 mosquitoes per hut. It is suggested that more insecticide-treated bed nets be used in this area for effective control of malaria vectors and further studies be conducted to determine the role of An. merus in malaria transmission.